Amorphous carbon supported MoS₂ nanosheets as effective catalysts for electrocatalytic hydrogen evolution.
Amorphous carbon supported MoS₂ nanosheets as effective catalysts for electrocatalytic hydrogen evolution.
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DOI：
10.1039/c4nr01885k
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发表时间：
2014-08
期刊：
影响因子：
6.7
通讯作者：
Xue Zhao;Hui Zhu;Xiurong Yang
中科院分区：
文献类型：
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作者：
Xue Zhao;Hui Zhu;Xiurong Yang
采用水热法制备了无定形碳负载的MoS_4催化剂，并对其进行了热处理，首次将其用作析氢反应的催化剂。在此，我们展示了一种制备策略，通过该策略，可以原位同时形成MoS和碳材料。如扫描电子显微照片所示，MoS纳米片垂直地形成在碳纳米球上。这种独特的形貌可以暴露出大量的MoS层边缘作为HER的活性位点，而下面的无定形碳有效地提高了导电性。以无定形碳为载体，优化了催化剂的制备工艺，该催化剂具有较高的电催化HER活性，起始电位低至80 mV，阴极电流密度大，稳定性好。值得注意的是，测量到的塔菲尔斜率为每十倍40 mV，这远远超过了以前的MoS催化剂的活性，并表明MoS催化的HER的Volmer-Heyrovsky机理。
Amorphous carbon supported MoS₂, which was elaborately prepared by using a facile hydrothermal method followed by annealing, is first employed as a catalyst for the hydrogen evolution reaction (HER). Herein, we demonstrate a preparation strategy, by which MoS₂ and carbon materials could be formed in situ and simultaneously. The MoS₂ nanosheets are vertically formed on the carbon nanosphere, as illustrated in the scanning electron micrograph. The unique morphology can expose abundant edges of the MoS₂ layer as active sites for the HER, while the underlying amorphous carbon effectively improves the conductivity. By means of employing amorphous carbon as a substrate, an optimized catalyst was developed, which exhibited enhanced catalytic activity for the electrocatalytic HER with an onset potential as low as 80 mV, extremely large cathodic current density and excellent stability. Notably, a Tafel slope of 40 mV per decade was measured, which exceeds by far the activity of previous MoS₂ catalysts and suggests the Volmer-Heyrovsky-mechanism for the MoS₂-catalyzed HER.